Collapsing taper-thread tap



Nov. 25, 1930. A. F. BREITENSTEIN I 4 COLLAPSIBLE PAPER THREAD TAP Filed May 7, 1928 3 Sheets-Sheet l Nov. 25, 19M. A. F. BREITENSTEIN COLLAPSIBLE TAPER THREAD TAP Filed 5 7, 1928 3 Sheets-Sheet 5 I u A v v.

Patented Nov. 25. 1930 UNITED STATES PATENT OFFICE i ALBERT r. rnm'rnnsrmn, or mew HAVEN, connnorrco'r. .assrenon 'ro 'rfiE,v

GEOMETRIG TOOL 00., or NEW HAVEN, commcrrcur, A conrormrron COLLAPSING TAPER-THBEAD ar I Application fi1ed May 7,

My invention relates to an improved collapsing taper-thread tap, the object being to produce a compact, sturdy,v convenient, accurate, easily-adjusted fixture, constructed with particular reference to reducing the len h of the fixture tothe minimum and to t e exclusion of chips-and all foreign matter from its interior.

With these ends in view, my invention consists in a collapsing, taper-thread tap hav ng certain details of construction as will be hereinafter described and particularly pointed out in the claims.

In the accompanying drawings:

Fig. 1 is a view in side elevation of my improved collapsing taper-thread tap, with the partsthereof shown in position to start cutting; a

Fig. 2 is a view thereof in front elevation; Fig. 3 is an enlarged-scale broken view in vertical longitudinal section with the parts thereof in thesame positions as shown in Fig. 1;

' Fig. 4 is a similar view with the parts 1n the positions due to them at the end of the cutting operation and at the instant the collapsing action ofthe tap begins;

' Fig. 5 is a corresponding view, showing the parts of the tap in their fully-collapsed position; v 1 1 Fig. 6 is a broken detail sectional view on the line 6-6 of Fig. 2;

Fig. 7 1s a view in transverse section on" I the line 77 of Fig. 3;

Fig. 8 is a view in transverse section-on the line 8-8 of Fig. 3;

Fig. 9 is a detached perspective view of the sleeve which carries the looking and taper-controlling dog;

Fig. 10 is a similar view of the combined locking and taper-controlling dog;

Fi 11 is a similar view of the taper-controlling cam; and

Fig. 12 is a similar broken view of the inner end of the plunger.

In carrying out my invention as herein shown, I employ a cylindrical or rod-like ta -body 15 having in its forward end an axial bore 16 forthe reception of a plunger 17 the tapered forward end of which is' .1928. serial no. 275,661.

formed with converging under-cut L-shaped ribs 18 which are interlocked with corresponding ribs 19 formed in the inner edges of chasers 20, the outer edges of which are formed with thread-cutting teeth 21 which converge from their rear to their forward ends in the usual manner. The said chasers are respectively located in four equidistant radial slots 23 formed in the f0rward end of the said tap-body 15 and are normally held in place against forward displacement by a cap 24 fastened by screws 25 entering the forward end of the body 20. Upon the forward portion of the body and axially-movable thereupon I mount a dogcarrying sleeve 26. A tripping-sleeve 27 axially-movable independently of the said dog-carrying sleeve 26 bears at its forward end thereupon and at its rear end upon the peripheryof an annular locking-flange 28 forwardly-projecting from an adjustingring 29 provided with internal threads 30 meshing with'external threads 31 upon the tap-body 15.

At its rear end, the said plunger 17 is provided with an inclined transverse slot 32, rectangular in cross-section and having an inclined forward wall 33 and an inclined rear wall 34 forming, in eifect,' parallel cam-surfaces. This slot receives a close-fitting forwardly-inclined tongue '35 formed integral with and projecting radially inward from the center of a segmental combined locking and taper-controlling dog 36 having radialmovement in a relatively-wide transverse slot 37 in the lower face of the rear end of the sleeve Y 26 by which it is carried. The parallel front and rear faces respectively of the said tongue constitute, in effect, cam-surfaces for 00-110- tion with the forward and rear walls 33 and 34 of the slot 32 above described, all of which are acutely-inclined with respect to the transverse axis of the tap.

For moving the do 36 radially into its locking position and enee for moving the plunger 17 forward and the chasers 20 outward, the respective ends of the dog are formed with sockets '38 for the reception of helical springs 39, the opposite ends of which are seated in sockets 40 formed in the bottom walls of the transverse slot 37 in the dogcarryin sleeve 26, the said springs being guided by pins 41 fastened in the said sleeve and projecting outward from the sockets 40 therein.

On the other hand, the dog 36 is moved radially inward against the urge of the springs 39, for drawing the plunger 17 inward and hence retracting the chasers 21 by means of a wedge-shaped taper-controlling cam 42 located in a longitudinal groove 43 formed within the tripping-sleeve 27 The said cam 42 projects into a longitudinal peripheral groove 44 formed in the dog-carrying sleeve 26, whereby the tripping-sleeve is prevented from relative rotary movement with respect to the said sleeve 26. The said cam 42 is secured inplace, with capacity for longitudinal adjustment, by means of a binding-screw 45 threaded into its forward end and passing through a longitudinal slot 46 in the forward end of the tripping-sleeve 27.

While the chasers are permitted to gradually recede and cut a taper thread, they are prevented from prematurely colla sing by the engagement of the rear face 0 the dog 36 with the forward edge of the lockingfiange 28, as shown in Fig. 3, which projects forwardly from the adjusting-ring 29 as already described,

The described engagement of the forward edge of the locking-flange 28 with the rear face of the dog prevents the fixture from bebottoms of the said sockets 48, while their projecting forward ends engage with two radial abutment-pins 49 (Fig. 6) mounted in the tap body 15. The inner walls of the forward ends of the said sockets 48 are cut away as at 50 for the reception of the said abutmentins 49, whereby the sleeve 26 is prevente from relative rotary movement upon the tap-body.

For the gradual recession of the chasers 21 forcuttin a taper thread and also for ultimately co apsing them, I employ a circular operating-plate 51 having a central clearance-opening 52 and carried at a right angle to the axis of the tap by a pair of parallel arms 53 longitudinally adjustable in oppositely-located grooves 54 formed in the periphery of the tripping-sleeve 27, the said arms being adjustably secured in place by means ofbinding-screws 55 passing throng longitudinal slots 56 in the said arms and into the said sleeve.

For re-setting the fixture after it has completed a taper-thread cutting operation and has been collapsed for withdrawal from the work, I employ a doubly-fulcrumed leverhandle 57 mounted in the tripping-sleeve 27 on a transverse pin 58. The said handle is formed with a spherically-contoured boss 59 through which the pin 58 passes and which fits snugly in a contoured passage 60 in the said sleeve 27, whereby chips or any foreign material are prevented from working into the interior of the fixture, the passage or bearing-seat 60 having its outer portion flared as at 61 for permitting the rocking movement of the handle. The inner end of the handle projects through a clearance-slot 62 in the dog-carrying sleeve 26 and is provided with a ball-end 63 which fits into a socket 64 in the tap-body 15, as clearly shown in Fig. 3, the upper face of the plunger being formed with a shallow recess 65 for clearing the said ball-end 63 of the handle.

The operation of my improved fixture is as follows:

Assuming that the parts are in the positions shown in Fig. 3, the tap will be moved toward the Work or the work toward the I tap,-more commonly the former. In either event, the chasers 20 enter the work, the outer end of which is engaged with the forward face of the trippinglate 51. ASSllmlLa'. now, for the purpose 0 description, that the tap is being moved toward the work, the t pping-plate 51, on coming in contact with the work, will itself come to rest and arrest the tripping-sleeve 27 and taper-controlling cam 42, while the tap-body 15, dog-.carrying sleeve 26, dog 36, adjusting-ring 29, plunger 17 and the chasers 20 will move forward. As the parts move forward as described, the dog will ride up the cam 42 which will force it radially inward against the urge of the springs 39, whereby the rear face of its inclined tongue 35 will engage with the rear wall 34 of the slot 32 in the plunger 17 and gradually retract the same and so cause the chasers 20 to move inwardly or recede. The movement described continues until the rear corner 66 of the dog reaches the position in which it is shown in Fig. 4. At this moment the collapsing springs 47 assert themselves and snap the dog-carrying sleeve 26, the dog 36 and the plunger 17 rearward with respect to the tap-body 15, whereby the parts are moved into the positions shown in Fig. 5, in which the chasers 20 are fully collapsed and freed from the work, completing the threading cycle of the tap. The handle 57 is now manually rocked forward against the tension of the collapsing springs 47 from the position in which it is shown in Fig. 5 into the position in which it is shown in Figs, 1 and 3, whereby the fixture is re-set for another taper-threading operation. When the handle is rocked forward as described, the tripping-sleeve 27 is also moved forward, with the effect of engaging the fiange 67 at the forward end of the dog-carrying sleeve, which is then picked up and carried forward with it with respect to the tap-body 15. The dog 36 will be carried forward with the dog-carrying sleeve 26 clear of the forward edge of the lockingfiange 28, whereupon the springs 38 will assert themselves to snap the dog radially outward into the position in which it is shown in Fig. 3. This outward movement of the dog causes the forward edge of its forwardly-inclined tongue 35 to co-act with the forward wall 33 of the slot 32 in the plunger 17 to move the same forward with respect to the tap-body 15 and thus expand the chasers 20.

If desired, the tripping-plate 51 may be dispensed with and the tripping of the tap effected by the handle 57, or by an ordinary yoke installed inthe machine in which the tap is used in position to enter an annular groove 68 in the inner end of the trippingsleeve 27, this being common practice in the tripping of such threading fixtures.

By constructing my improved collapsing taper-thread tap in the manner described with operatingand dog-carrying sleeves, I reduce the len th of the tap to the minimum to obvious advantage, gaining space and lessening lateral deflection. I am also enabled by'the construction described to exclude chips and foreign matter from the inside of the fixture. Furthermore, on account of the very large surfaces resulting from the use of a segmental locking-dog with its internally-arranged radial ton ue in conjunction.

with an annular lockingange, I distribute the wear over large surfaces and hence lengthen the life of the fixture and heighten the accuracy of its performance. F urthermore, by employing an adjusting-ring as shown, 0 erable from the rear of the fixture, I am ena led to adjust it at any time with far more convenience than from its forward end, as has been done heretofore.

By acutely-inclining the parallel front and rear walls of the slot 32 in the plunger 17 with respect to the transverse axis of the tap,

and similarly inclining the contacting-surfaces of the tongue 35 of the dog 36, the said dog positively effects the movement of the i said plunger in both directions and locks the same against being moved in either direction by extraneous forces acting through the chasers.

I claim:

1. In a collapsing ta er-thread tap, the combination with a tap-body, radi lly-movunger located axially within the tap-body for oper- 'ating the chasers and having t o inclined parallel cam-surfaces, an axially-movable dog-carrying sleeve mounted upon the tap" body, an axially-movable tripping sleeve bearing upon the said dog-carrying sleeve, a

combined locking and taper-controlling dog carried by the said dog-carrying sleeve and having two parallel forwardly-inclined operating-faces co-acting with the cam-surfaces of the said plunger for operating the same, a

taper-controlling cam carried by the said tripping-sleeve and co-acting with the dog for (positively movin the same bodily inwar and a locking-abutment co-acting with the dog for maintaining the chasers in their 1 said transverse slot and co-acting with the forwardly-inclined front and rear walls thereof for positively reciprocating the plunger in both directions, ataper-controlling cam carried by the said tripping-sleeve and co-actin with the said dog for moving the same bo ily inward, and a locking-abutment co-acting with the dog for maintaining the chasers in their thread-cutting positions.

3. In a collapsing-taper-tl1read tap, the combination with a tap-bod radially-movable chasers mounted therein, a plunger located axially within the tap-body for operatlng the 'chasers. an adjusting-ring threaded upon the said tap-body, an axially-movable dog-carrying sleeve mounted directly upon the tapody, an axially-movable trlppingsleeve bearing at its forward end upon the said dog-carrying sleeve and at its rear-fiend upon the said adjusting-ring, a combined;{.. locking and taper-controlling dog carried by" the said dog-carr ing sleeve and having a forwardly-incline arm co-actin with the saidplunger for reciprocating the same, a taper-controlling cam carried by the said tripping-sleeve and co-acting with the'said dog for moving the same bodily inward, and a locking-abutment co-acting with the dog for maintaining the chasers in their thread-cutting positions. 7

4. In a collapsing taper-thread tap, the combination with a tap-body, radially-movable chasersmounted therein, a plunger located axially within the tap-body for operating the c asers, a cup-sha ed adjustingring threaded upon'the tapody and provided with a forwardly-projectin annular locking-flange, an axially-move le carrying sle fe mounted bearing at its forward end upon the said dogcarrying sleeve and at its rear end upon the periphery 'of the said locking-flange, a combined locking and taper-controlling dog carried by the said dog-carrying sleeve, co-acting with the said locking-flange for maintaining the said dog-carrying sleeveand I having a 'orwardly-inclined arm entering the dog-' directly upon the tap-body, anaxially-movable tripping-sleeve the said chasers in their cutting positions, and having a forwardly-inclined arm co-acting with the said plunger for reciprocating the same, and a taper-controlling cam carried by the said tripping-sleeve and "co-acting with the dog for moving the same bodily inward.

5. In a collapsing taper-thread tap, the combination with a tap-body, radially-movable chasers mounted therein, a plunger located axially within the tap-body for oper ating the chasers, a cup-shaped adjustingring threaded upon the tap-body and having a forwardly-projecting annular lockingflange, an axially-movable dog-carrying sleeve mounted directly upon the tap-body and at its rear end telescoping within the said locking-flange, an axiallymovable tripping-sleeve hearing at its forward end upon the said dog-carrying sleeve and at its rear end upon the'periphery of the said lockingflange, a combined locking and taper controlling dog carried by the said dog-carrying sleeve, co-acting with the said locking-flange for maintaining the chasers in their cutting positions, and having a forwardly-inclincd arm co-acting with the said plunger for reciprocating the same, and a taper-controlling cam carried by the said tripping-sleeve and co-acting with the dog for moving the same bodily inward.

6. In a collapsing taper-thread tap, the combination with the tap-body, radially-movable chasers mounted therein, a plunger located axially within the tap-body for operating the chasers, a cup-shaped adjustingring threaded upon the tap-body and having a forwardly-projecting annular lockingflange, an axiallymiovable dog-carrying sleeve mounted directly upon the tapbody, an axially-movable tripping-sleeve hearing at its forward end upon the said dog-carrying sleeve and at its rear end upon,.the periphery of the said flange, a combinedlockihg and taper-controlling dog carried by the dog-carrying sleeve and having a forwardly-inclined arm co-acting with the plunger for reciprocating the same and having its rear face engaged with the forward edge of the said locking-flange, and a tapencontrolling cam carried by the tripping-sleeve and acting with the dog for moving the same bodily inward.

7. In a collapsing taper-thread tap, the combination with a tap-body, of radiallymovable chasers mounted therein, a chaseroperating plunger axially located within the said tap-body and formed with a slot having parallel inclined front and rear walls, an axially-movable dog carrying sleeve carried by the tap-body and formed upon the lower face of its rear end with a segmental transverse slot, an axially-movable trippingsleeve bearing upon the said dog-carrying sleeve, a segmental combined locking and taper-controlling dog located in the said segmental slotin the dog-carrying sleeve and having a centrally-arranged forwardlyinclined radial tongue, the parallel front and rear faces of which coact with the correspondingly-inclined front and rear walls of the slot in the said plunger for positively reciprocating the same in both directions, a tapercontrolling cam carried by the said trippingsleeve and coacting with the said dog for moving the same bodily inward, and a locking-abutment coacting with the said dog for maintaining the chasers in their thread-cutting positions.

8. In a collapsing taper-thread tap, the combination with a tap-body, radially-movable chascrs mounted therein, a plunger located axially within the tap-body for operating the chasers, an axially-movable dogcarrying sleeve mounted directly upon the tap-body, an axially-movable tripping-sleeve bearing upon the said dog-carrying sleeve, a combined locking and taper-controlling dog carried by the said dog-carrying sleeve and having a forwardly-inclined arm co-acting with the said plunger for reciprocating the same, a taper-controlling cam carried by the said tripping-sleeve and co-acting with the dog for moving the same bodily inward, spring-means constantly urging the said dog radially outward, and a locking-abutment co-acting with the dog for maintaining the chasers in their thread-cutting positions.

9. In a collapsing taper-thread tap, the combination with a tap-body, radially-1novable chasers mounted therein, a plunger locat ed axially within the tap-body for operating the chasers, a cup-shaped adjusting-ring threaded upon the tap-body and having a forwardly-projecting annular locking-flange, an axially-movable dog-carrying sleeve bearing upon the said tap-body, an axially-mov able tripping-sleeve bearing at its forward end upon the said dog-carrying sleeve and at its rear end upon the periphery of the said locking-flange, a combined locking and tapercontrolling dog carried by the said dog-carrying sleeve and having a forwardly-inclined arm coacting with the said plunger for reciprocating the same, a taper-controlling cam carried by the tripping-sleeve and co-acting with the dog for moving the same bodily inward, and a hand-lever pivotally mounted in the said tripping-sleeve and extending through a slot in the dog-carrying sleeve into a socket in the said tap-body.

10. In a collapsing taper-thread tap, the combination with a lap-body, radially-movable chasers mounted therein, a plunger located axially within the tap-body for operating the chasers and having two parallel camsurfaces acutely-inclined with respect to the transverse axis of the tap, a substantially radially-movable combined locking and taper-controlling dog having two parallel opcrating-faces acutely-inclined to the transverse axis of the tap and respectively co-acting with the cam-surfaces of the said plunger for positively reciprocating the same in both directions and positively locking it against movement in either direction by extraneous forces, and means co-acting with the said dog for operating thesame to positively effect the retraction of the plunger, whereby the said dog effects the reciprocationof the said plunger in both directions and'the plunger is prevented from moving the dog in either direction.

In testimony whereof, I have signed this specification.

ALBERT F. BREITENSTEIN. 

